What are the specs for this Transformer?

The correct replacement for Carrier model C4850C48AY02761 is this exact part. It is the factory-specified replacement with exact OEM specifications. Using a part with different specifications can cause equipment damage or void your warranty. You can verify this by checking the data plate on your Carrier equipment which lists the model number C4850C48AY02761.

Is this transformer compatible with Bryant or Payne systems too?

Many Carrier parts are cross-compatible with Bryant and Payne systems since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across multiple brand labels with different model numbers. To verify cross-compatibility, check your Bryant or Payne equipment service manual for cross-compatible part numbers, or contact info@nationalhvacparts.com with your model number for confirmation.

Carrier

OEM Carrier Transformer 40VA 120V-24V for C4850C48AY02761

Name: OEM Carrier Transformer 40VA 120V-24V for C4850C48AY02761
Brand: Carrier
SKU: CARRIE-C4850C48AY02761-TRANSFORMER-HT01BD236
Price: 47.25 USD
Availability: InStock

SKU: CARRIE-C4850C48AY02761-TRANSFORMER-HT01BD236 Brand: Carrier

✓ Guaranteed to fit C4850C48AY02761 — or your money back. Terms

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014

SAM.gov Registered

Govt POs Accepted

OEM Carrier 40VA Control Transformer HT01BD236 for Model C4850C48AY02761

This is the factory OEM replacement transformer (part number HT01BD236) for the Carrier C4850C48AY02761 packaged unit. The transformer steps down 120V line voltage to the 24V signal voltage required by your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this component fails, the entire control circuit goes dark — the thermostat loses power, the system won't respond to any call for heating or cooling, and in many cases the unit appears completely dead despite having line voltage present.

Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD236 | Factory-matched thermal protection and core lamination for long service life
OEM vs Generic: OEM transformers are wound and tested to Carrier's exact VA rating and insulation class. Undersized or off-spec generic transformers can overheat under contactor coil inrush loads, causing nuisance tripping or premature failure and potentially damaging downstream control boards.
Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 0V before touching wiring). Photograph or label all wire connections before removal. Reinstallation is straightforward — two primary leads and two secondary leads.
Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier C4850C48AY02761 packaged unit. Cross-reference OEM part number HT01BD236 against your unit's wiring diagram and data plate to confirm 120V primary and 24V/40VA secondary ratings before ordering. Our parts specialists are available to verify fitment — order with confidence.

Shipping Information

Orders placed before 3PM CST ship same business day
Standard delivery: 2-5 business days
Express shipping available at checkout
Free shipping on orders over $99
Tracking number emailed upon shipment

Return Policy

30-day returns on unused parts in original packaging
Electrical parts (capacitors, contactors, control boards) are final sale once installed
Email info@nationalhvacparts.com to initiate a return
Refunds processed within 5-7 business days

OEM Carrier Transformer 40VA 120...

$47.25

Frequently Asked Questions

Does this Transformer fit my Carrier C4850C48AY02761?

Yes. This is the factory-specified OEM transformer for the Carrier C4850C48AY02761. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.

How do I replace the transformer on my Carrier C4850C48AY02761?

Difficulty: Medium (30–45 min)
Step 1: Turn off breaker. Step 2: Photo wiring connections. Step 3: Disconnect wires from old transformer. Step 4: Remove mounting hardware. Step 5: Install new transformer, reconnect wires matching voltage ratings. Step 6: Verify 24V output with multimeter.

My thermostat has no power. What failed?

Thermostat with no display = failed 24V transformer (or blown control board fuse). Check the 3A/5A fuse on the control board first ($1–$5 fix). If fuse is good but no 24V output from transformer, replace transformer.

Is this transformer compatible with Bryant or Payne too?

Many Carrier parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.

Should I use OEM or aftermarket for my Carrier transformer?

OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.

How fast does National HVAC Parts ship?

Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.

Menu

OEM Carrier Transformer 40VA 120V-24V for C4850C48AY02761

OEM Carrier 40VA Control Transformer HT01BD236 for Model C4850C48AY02761

Shipping Information

Return Policy

Frequently Asked Questions